Allow since="TBD" for rustc_deprecated

[bstrie]

Closes #78381.

This PR only affects #[rustc_deprecated], not #[deprecated], so there is no effect on any stable language feature.

Likewise this PR only implements since="TBD", it does not actually tag any library functions with it, so there is no effect on any stable API.

Overview of changes:

• rustc_middle/stability.rs:
  • change deprecation_in_effect function to return false when since="TBD"
  • tidy up the compiler output when a deprecated item has since="TBD"
• rustc_passes/stability.rs:
  • allow since="TBD" to pass the sanity check for stable_version < deprecated_version
  • refactor the "invalid stability version" and "invalid deprecation version" error into separate errors
• rustdoc: make since="TBD" message on a deprecated item's page match the command-line deprecation output
• tests:
  • test rustdoc output
  • test that the deprecated_in_future lint fires when since="TBD"
  • test the new "invalid deprecation version" error message

[rust-highfive]

r? @oli-obk

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[bors]

☔ The latest upstream changes (presumably #80041) made this pull request unmergeable. Please resolve the merge conflicts.

Note that reviewers usually do not review pull requests until merge conflicts are resolved! Once you resolve the conflicts, you should change the labels applied by bors to indicate that your PR is ready for review. Post this as a comment to change the labels:

@rustbot modify labels: +S-waiting-on-review -S-waiting-on-author

[oli-obk]

r=me (needs rebase)

[bstrie]

Er, one moment, something went weird with the rebase...

[rust-log-analyzer]

The job mingw-check of your PR failed (pretty log, raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

[command]/usr/bin/git submodule foreach --recursive git config --local --name-only --get-regexp 'http\.https\:\/\/github\.com\/\.extraheader' && git config --local --unset-all 'http.https://github.com/.extraheader' || :
[command]/usr/bin/git config --local http.https://github.com/.extraheader AUTHORIZATION: basic ***
##[endgroup]
##[group]Fetching the repository
[command]/usr/bin/git -c protocol.version=2 fetch --no-tags --prune --progress --no-recurse-submodules --depth=2 origin +d72038a0b80906e8951ec23265d0e3c0860dbcf9:refs/remotes/pull/79877/merge
---
    Checking rustc-rayon v0.3.0
    Checking tempfile v3.1.0
    Checking regex v1.3.9
    Checking rustdoc v0.0.0 (/checkout/src/librustdoc)
error[E0277]: the trait bound `str: __Deref` is not satisfied
    --> src/librustdoc/html/render/mod.rs:2282:26
     |
2282 |                 if since == "TBD" {
     |                          ^^ the trait `__Deref` is not implemented for `str`
     |
     = note: required because of the requirements on the impl of `std::cmp::PartialEq<str>` for `SymbolStr`
     = note: required because of the requirements on the impl of `std::cmp::PartialEq<&str>` for `&SymbolStr`

error[E0277]: the size for values of type `str` cannot be known at compilation time
    --> src/librustdoc/html/render/mod.rs:2282:26
     |
2282 |                 if since == "TBD" {
     |                          ^^ doesn't have a size known at compile-time
     |
     = help: the trait `std::marker::Sized` is not implemented for `str`
     = note: required because of the requirements on the impl of `std::cmp::PartialEq<str>` for `SymbolStr`
     = note: required because of the requirements on the impl of `std::cmp::PartialEq<&str>` for `&SymbolStr`
error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0277`.
error: could not compile `rustdoc`

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @rust-lang/infra. (Feature Requests)

[jyn514]

@bors r=oli-obk

[bors]

📌 Commit 1e1ca28 has been approved by oli-obk